C Language Program

1. Chapter 2
C Language Program
Mr.Warawut Khangkhan
Twitter: http://twitter.com/awarawut
Facebook: http://www.facebook.com/AjWarawut
E-Mail: awarawut@hotmail.com
Mobile: 083-0698-410

2. Contents
F C
C
F C
F C
C
C
F (Expression) C
Mr.Warawut Khangkhan Chapter 2 C Language Program 2

3. Contents (Cont.)
F C
F C
Mr.Warawut Khangkhan Chapter 2 C Language Program 3

4. Mr.Warawut Khangkhan Chapter 2 C Language Program 4

5. BCPL B C
Basic Combined . . 2515
Programming PDP-7
Language (UNIX)
. . 2513
Mr.Warawut Khangkhan Chapter 2 C Language Program 5

6. F C
Mr.Warawut Khangkhan Chapter 2 C Language Program 6

7. F C
(High Level Language)
F (OS Independent)
F F (Hardware
Independent)
F (Structure Language)
Mr.Warawut Khangkhan Chapter 2 C Language Program 7

8. C
Mr.Warawut Khangkhan Chapter 2 C Language Program 8

9. C
----
----
----
Source Code F
F F source code
Mr.Warawut Khangkhan Chapter 2 C Language Program 9

10. C
F (Compiler)
F F F F F
F F F F F F
F
Mr.Warawut Khangkhan Chapter 2 C Language Program 10

11. F
Main()
F
F F
{
printf(“XX”);
printf(“YY”);
}
F F F
F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 11

12. F F C
F F F
F F F copy
disk F F
source code
F F F (Binary)
executable file (.exe)
Mr.Warawut Khangkhan Chapter 2 C Language Program 12

13. F C
Mr.Warawut Khangkhan Chapter 2 C Language Program 13

14. F C
// Comment
#include <stdio.h> /* Hearder file */
… Data declarations …;
int main( ) {
… Executable statement …;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 14

15. F C
// Comment
#include <stdio.h> /* Hearder file */
… Data declarations …;
int main( ) {
… Executable statement …;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 15

16. F C
// Comment
#include <stdio.h> /* Hearder file */
… Data declarations …;
Header File F
int main( ) { F F
… Executable statement …;
} F F F F F
F
Preprocessor Directive
Mr.Warawut Khangkhan Chapter 2 C Language Program 16

17. F C
// Comment
#include <stdio.h> /* Hearder file */
… Data declarations …; F
int main( ) {
… Executable statement …;
} data_type variable ;
Mr.Warawut Khangkhan Chapter 2 C Language Program 17

18. main Function F F
F C
// Comment { }
#include <stdio.h> /* Hearder file */
function
function main
… Data declarations …; F
int main( ) {
… Executable statement …;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 18

19. F C
Mr.Warawut Khangkhan Chapter 2 C Language Program 19

20. F C
F F F F { }
F (function) F main( )
F ; (semi colon)
F F
F , (comma) F
(Parameters)
F /* … */ F F F F
compiler
Mr.Warawut Khangkhan Chapter 2 C Language Program 20

21. Example ex01.c
ex01.c
#include <stdio.h> //#include “stdio.h”
#include <conio.h>
int main( ) {
printf(“Hello World!!!”);
getch( );
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 21

22. Example ex02.c
ex02.c
#include <stdio.h>
#include <stdlib.h>
int main( ) {
printf(“Hello World!!!”);
system(“PAUSE”);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 22

23. Example ex03.c
ex03.c
#include <stdio.h>
#include <stdlib.h>
int main( ) {
printf(“Hello “);
printf(“World!!!”);
printf(“n”);
system(“PAUSE”);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 23

24. Example ex03.c
ex03.c
#include <stdio.h>
#include <stdlib.h>
int main( ) {
printf(“Hellon “);
printf(“World!!!”);
system(“PAUSE”);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 24

25. C
Mr.Warawut Khangkhan Chapter 2 C Language Program 25

26. C
(Variable) F
F F F
F F F F
F F F F F F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 26

27. C
(Scalar) F F
F
(Array) F F
F F
F (Structure)
F F F F F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 27

28. (Scalar)
F 2
Integer types
Real types
Mr.Warawut Khangkhan Chapter 2 C Language Program 28

29. Mr.Warawut Khangkhan Chapter 2 C Language Program 29

30. Mr.Warawut Khangkhan Chapter 2 C Language Program 30

31. Example limit.c
#include <stdio.h>
#include <limits.h>
int main( ) {
printf(“Minimum char = %dn“, CHAR_MIN);
printf(“Maximum char = %dn”, CHAR_MAX);
printf(“Minimum int = %in”, INT_MIN);
printf(“Maximum int = %in”, INT_MAX);
return 0;
}
Minimum char = -128, Maximum char = 127
Minimum int = -32768, Maximum int = 32767
Mr.Warawut Khangkhan Chapter 2 C Language Program 31

32. F
( )
Char 1 ASCII 1
0 255
Int 2 –32768 32767
Short 2 –32768 32767
Long 4 ±
2000
Unsigned Unsigned short = 2 0 65535
Unsigned long = 4 0 4000
Float 4 10x x
–37 +38
Double 8
Mr.Warawut Khangkhan Chapter 2 C Language Program 32

33. C
F F F a-z A-Z _
F A-Z a-z
0-9 _
F F F F F F
F
F F F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 33

34. C (Cont.)
F (Reserved Word)
auto break case char const
continue default do double else
enum extern float for goto
if int long register return
short signed sizeof static struct
switch typedef union unsigned void
volatile while
Mr.Warawut Khangkhan Chapter 2 C Language Program 34

35. F C
: :
average pi 3rd_entry all$done
number_of_students the end int
entry_total
entryTot
al
all_total allTotal
Mr.Warawut Khangkhan Chapter 2 C Language Program 35

36. C
: int num;
type name; float y;
: char c;
double salary;
type
name ( C)
Mr.Warawut Khangkhan Chapter 2 C Language Program 36

37. C
:
type name = value;
:
type
name ( C)
value F F
int num = 10;
float y = 5.2;
char c = ‘A’;
double salary = 25.00;
Mr.Warawut Khangkhan Chapter 2 C Language Program 37

38. C
Mr.Warawut Khangkhan Chapter 2 C Language Program 38

39. C
(Operator) F F
F F (+), (-), (*)
(/) F
Mr.Warawut Khangkhan Chapter 2 C Language Program 39

40. C (Cont.)
Assignment Statement
Arithmetic Operators
Increment/Decrement Operators
Other Assignment Operators
Comparison Operators
Logical Operators
Mr.Warawut Khangkhan Chapter 2 C Language Program 40

41. Assignment Statement
F F F
F =
:
variable = expression;
:
variable
expression F F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 41

42. Assignment Statement (Cont.)
Mr.Warawut Khangkhan Chapter 2 C Language Program 42

43. Example term.c
#include <stdio.h>
int main( ) {
int teerm, term_2, term_3;
term = 3 * 5; term = 15
term_2 = 2 * term; term_2 = 30
term_3 = 3 * term; term_3 = 45
printf("term = %dn", term);
printf("term_2 = %dn", term_2);
printf("term_3 = %dn", term_3);
return 0;
} Mr.Warawut Khangkhan Chapter 2 C Language Program 43

44. Arithmetic Operators
F F F (+), (-),
(*) (/) F
F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 44

45. Mr.Warawut Khangkhan Chapter 2 C Language Program 45

46. Example math1.c
math1
#include <stdio.h>
a+b=7
int main( ) { a-b=3
a * b = 10
int a = 5, b = 2, z;
z = a + b;
printf(“a + b = %dn”, z);
z = a - b;
printf(“a - b = %dn”, z);
z = a * b;
printf(“a * b = %dn”, z);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 46

47. Example math2.c
math2
#include <stdio.h>
int main( ) { div = 2
mod = 1
int a = 5, b = 2, z;
z = a / b;
printf(“div = %dn”, z);
z = a % b;
printf(“mod = %dn”, z);
// printf(“a %% b = %dn”, z);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 47

48. Increment/Decrement Operators
/ F 1
F 1 F ++
F 1 F --
int i = 5, j = 4;
i++; // i = i + 1; “i” becomes 6
--j; // j = j – 1; “j” becomes 3
++i; // i = i + 1; “i” becomes 7
Mr.Warawut Khangkhan Chapter 2 C Language Program 48

49. Mr.Warawut Khangkhan Chapter 2 C Language Program 49

50. Example inc_dec.c
#include <stdio.h>
n= 5
n= 6
int main( ) { n= 6
int n = 5; n= 7
printf(“n = %dn”, n);
printf(“++n = %dn”, ++n);
printf(“n++ = %dn”, n++);
printf(“n = %dn”, n);
return 0;
} Mr.Warawut Khangkhan Chapter 2 C Language Program 50

51. Example effect.c
#include <stdio.h>
int main( ) { 8
int value = 1, result;
result = (value++ * 5) + (value++ * 3);
printf("%dn", result);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 51

52. Other Assignment Operators
Mr.Warawut Khangkhan Chapter 2 C Language Program 52

53. Example other_ass.c
#include <stdio.h>
void main( ) { Before b = 1
After b = 6
int a = 5, b = 1;
printf(“Before b = %dn”, b);
b += a; // b = b + a;
printf(“After b = %dn”, b);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 53

54. Comparison Operators
Mr.Warawut Khangkhan Chapter 2 C Language Program 54

55. Logical Operators
Mr.Warawut Khangkhan Chapter 2 C Language Program 55

56. Table Logical Operators
A B A && B A || B !A
True True True True False
True False False True False
False True False True True
False False False False True
Mr.Warawut Khangkhan Chapter 2 C Language Program 56

57. F (EXPRESSION)
C
Mr.Warawut Khangkhan Chapter 2 C Language Program 57

58. F (Expression) C
F (Expression) F F
F F F
F
F y = 2x * 5, 2xy – 5 F
Mr.Warawut Khangkhan Chapter 2 C Language Program 58

59. F C (Cont.)
1. F C
F C F
F F
C
2. F F
F F
F F F
C F F F
F F* x F/
Mr.Warawut Khangkhan Chapter 2 C Language Program 59

60. F C (Cont.)
3. F F
F F
F C (&&, ||, !) F
F F F F F F
F
c && (a <= b), (b >= c) || (c <= a)
Mr.Warawut Khangkhan Chapter 2 C Language Program 60

61. F C (Cont.)
4. F
F F F F
F F F
F
a / b + 15 * c (a – b) * 10 / c
F F F
F C F
Mr.Warawut Khangkhan Chapter 2 C Language Program 61

62. 1 ()
2 !, ++, --, (typecast)
3 *, /, %
4 +, -
5 <, <=, >, >=
Mr.Warawut Khangkhan Chapter 2 C Language Program 62

63. (Cont.)
6 = =, !=
7 &&
8 ||
9 *=, /=, %=, +=, -=
Mr.Warawut Khangkhan Chapter 2 C Language Program 63

64. F
C
Mr.Warawut Khangkhan Chapter 2 C Language Program 64

65. F C
F F F F int + float
int – char
F F
F F
C F Casting 2
◦ F
◦ F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 65

66. F
F C F F
F
F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 66

67. F
Var. 1 Var. 2 Var. 3
char int chat -> int
int long int -> long
int unsigned int int -> unsigned int
int float int -> float
int double int -> double
float double float -> double
long double long -> double
double long double double -> long double

68. Example implicit.c
#include <stdio.h>
int main( ) {
int n = 5;
float f = 3.5, r;
r = 8.500000
r = n + f;
printf(“r = %fn”, r);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 68

69. F F
F
F F F
:
(type)expression;
:
type F
expression F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 69

70. Example explicit.c
#include <stdio.h>
n = 5.000000
int main( ) { f=3
int n = 5; n+f=8
float f = 3.2;
printf(“n = %fn”, (float)n);
printf(“f = %dn”, (int)f);
printf(“n + f = %dn”, (n + (int)f));
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 70

71. F
C
Mr.Warawut Khangkhan Chapter 2 C Language Program 71

72. C
F F F F
F F printf( ) F
F F F F
F F
:
printf ( format, exp.1, exp.2, …);
:
format F F
exp.1, exp.2 F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 72

73. C (Cont.)
Mr.Warawut Khangkhan Chapter 2 C Language Program 73

74. F
%d %i
%u
%0
%x
%f (6 )
%e E e
Mr.Warawut Khangkhan Chapter 2 C Language Program 74

75. (Cont.)
F
%c 1 (char)
%s F (string)
%p F (pointer)
Mr.Warawut Khangkhan Chapter 2 C Language Program 75

76. n F
t F F F 1 tab ( F 6 )
r F cursor F F
f F F F 1 F
b F 1
Mr.Warawut Khangkhan Chapter 2 C Language Program 76

77. Example control.c
#include <stdio.h>
5 10
int main( ) { 15
int a = 5, b = 10, c;
printf(“%dt%dn”, a, b);
c = a + b;
printf(“%d”, c);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 77

78. F putchar(
putchar( )
:
putchar (expression);
:
expression F F
F ‘ ’ F ‘A’
Mr.Warawut Khangkhan Chapter 2 C Language Program 78

79. Example putchar.c
#include <stdio.h>
Func. printf( ) : A
int main( ) { Func. putchar( ) : A
char ch = ‘A’;
printf(“Func. printf( ) : %cn”, ch);
printf(“Func. putchar( ) : ”);
putchar(ch);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 79

80. F F puts( )
:
puts (expression);
:
expression F F
F “ ” F “ABC”
Mr.Warawut Khangkhan Chapter 2 C Language Program 80

81. Example puts.c
#include <stdio.h>
int main( ) {
char str[ ] = “ABC”;
printf(“Func. printf( ) : %sn”, str);
printf(“Func. puts( ) : ”);
puts(str);
Func. printf( ) : ABC
return 0; Func. putchar( ) : ABC
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 81

82. F C
F F C F F
scanf( ) F F
F F F FF
(Integer), (Floating point),
(Character) F (String)
Mr.Warawut Khangkhan Chapter 2 C Language Program 82

83. F C (Cont.)
:
scanf (format, &var.1, &var.2, …);
:
format F F F
var.1, var.2 F F F
& F F string
F F & F
Mr.Warawut Khangkhan Chapter 2 C Language Program 83

84. F F F F scanf(
scanf( )
scanf(“%d %f %d”, &var1, &var2, &var3);
scanf(“%d/%f/%d”, &var1, &var2, &var3);
scanf(“%d,%f,%d”, &var1, &var2, &var3);
scanf(“%s %s %s”, var1, var2, var3);
Mr.Warawut Khangkhan Chapter 2 C Language Program 84

85. Example scanf1.c
scanf1
#include <stdio.h>
Input number to 2 value : 3 6
int main( ) {
a+b=9
int a, b, c;
printf("Input number to 2 value : ");
scanf("%d %d", &a, &b);
c = a + b;
printf("a + b = %dn", c);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 85

86. Example scanf2.c
scanf2
#include <stdio.h>
Input number to a : 3
int main( ) { Input number to b : 6
int a, b, c; a+b=9
printf("Input number to a : ");
scanf("%d", &a);
printf(“Input number to b : “);
scanf(“%d”, &b);
c = a + b;
printf("a + b = %dn", c);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 86

87. F F getchar(
getchar( )
getch(
getch( )
:
variable = getchar( );
variable = getch( );
:
variable F F
‘ ’ F ‘A’
getchar – F F 1 F (1 ) F
enter
getch – F F 1 F (1 ) F F
enter F F F F
Mr.Warawut Khangkhan Chapter 2 C Language Program 87

88. Example getchar1.c
getchar1
#include <stdio.h>
int main( ) {
char ch1;
printf(“Enter character 1 : “);
scanf(“%c", &ch1);
printf(“Result ch1 : %cn”, ch1);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 88

89. Example getchar2.c
getchar2
#include <stdio.h>
int main( ) {
char ch2, ch3;
printf(“Enter character 2 : ”);
ch2 = getchar( );
printf(“Result ch2 : %cn”, ch2);
printf(“Enter character 3 : “);
ch3 = getch( );
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 89

90. F F F gets( )
:
gets (expression);
:
expression F F
(F ) F “ ” F “ABC”
Mr.Warawut Khangkhan Chapter 2 C Language Program 90

91. Example scanf1.c
scanf1
#include <stdio.h>
int main( ) {
char str[ ] = “”;
printf("Input string : ");
scanf("%s", str);
printf("String : %s", str);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 91

92. Example gets.c
#include <stdio.h>
int main( ) {
char str[ ] = “”;
printf(“Input string: “);
gets(str);
printf(“String : %s”, str);
return 0;
}
Mr.Warawut Khangkhan Chapter 2 C Language Program 92